1. Field of the Invention
The present invention relates to a digital camera and a camera system equipped with a security function.
2. Description of Related Art
A plurality of sets of image data can be recorded into a detachable recording medium (such as a memory card) that may be loaded into a digital camera or a permanent recording medium installed as a built-in storage device in the digital camera. If the camera with a recording medium loaded therein or with built-in storage is lost or stolen, a third party will be easily able to access the images in the recording medium and may abuse them. In recent years, the capacity of recording media has increased greatly, allowing a large number of images to be recorded into a given recording medium. If such a recording medium ends up in the wrong hands, significant mischief may be done.
The need to effectively prevent unauthorized use of images or devices is addressed in Japanese Laid Open Patent Publication No. 2005-11151, which discloses a memory card that requires a password-based user authentication and in Japanese Laid Open Patent Publication No. 2005-216205, which discloses a system that executes a fingerprint-based user authentication.
However, the password-based authentication requires the user to enter his password each time he wishes to use the recording medium and is, therefore, inconvenient. There is an added concern that if the user forgets the password, he can no longer use the recording medium. Fingerprint authentication or palm print authentication requires the user to preregister his fingerprint or palm print and the user may find the task of preregistration inconvenient. Furthermore, since a fingerprint or palm print reading device must be installed in the system, the camera system is bound to become bigger and more complicated.